1. Field
The invention relates in general to a system for collecting milk from the teats of the animal being milked and transporting the milk through separate hose lines to a common milk line or pail. More particularly, the invention relates to a system employing hose lines made of silicone rubber and a novel collector member which brings the hose lines together. A teat cup employing a built in valving means is also provided for closing individual hose lines when a teat cup and its respective hose line fall from a teat of the animal being milked.
2. State of the Art
The construction and design of automatic milking apparatus has been recognized as a very important consideration in the dairy industry. Bacterial contamination of the milking machines contributes directly to mastitis, and much effort has been made in hygienic precautionary measures as well as in the design and construction of the milking apparatus.
Research has recently shown that potential habitats for bacteria not only include such areas as the underside of milk tube ferrules, rubber gaskets and other cracks and crevices between parts in conventional claws used in milking machines, but also include microhabitats created by microscopic surface cracks which exist in the rubber tubing and inflations used in the milking machines. The surface cracks of conventional rubber parts become more severe with usage. The use of silicone rubber inflations in automatic milking machines has recently become feasible. The use of silicone rubber for milk hose lines as well as for inflations is highly desirable, inasmuch as silicone rubber parts do not exhibit surface cracks as experienced with conventional rubber parts, and the potential habitats for bacterial propagation are greatly minimized. Silicone rubber parts do not exhibit surface cracks over their entire lifespan. Unfortunately, use of silicone rubber for the vacuum hose lines of the milking cups has not been feasible because the ferrules on the claws of the milking apparatus readily cut through the silicone rubber which is inherently susceptible to puncture and tear damage especially in areas where the silicone rubber is stressed.
It has been found that silicone rubber hose lines can be connected directly between the nipples on the milking cups and the milk pipe or pail. However, such a system is not practical. The separate hose lines required separate vacuum shut-off means as well as means to close off all vacuum hose lines simultaneously. The separate hose lines are cumbersome and subject to getting entangled and damaged, and a system of identifying corresponding hose lines and milking cups is needed to facilitate practical application of the milking cups to the animal being milked.
Even when fastidious hygienic procedures are followed to minimize bacterial contamination, mastitis is still a problem. It has been found that unstable vacuum variations occur within the milking cups of automatic milking apparatus. The unstable vacuum conditions can cause bacteria laden milk to flow backward in the vacuum hose lines. Under certain conditions, such as when one of the teats which are being milked has reached the end point of milking, milk can be forced backward into the teat by pressure differentials across the teat opening. This problem was discussed in U.S. Pat. No. 4,253,420, and, as explained therein, one way which has been tried to avoid the undesirable pressure variations and the return flow of milk contacting the tip of the teat is to provide an enlarged volume in the collecting piece. A quarter milking machine and a collecting piece for valving the four vacuum hoses from the milking cups are proposed in U.S. Pat. No. 4,253,420, wherein the collecting piece comprises metal rotating parts having alignment ports therein and ferrules for connection of the vacuum hoses thereto. The rotatable parts must be closely machined to maintain proper seal. Milk contacts the metal ferrules and parts in the collecting piece, and the cracks and crevices are present to form a habitat for bacteria. Further, vacuum hose lines of silicone cannot be used with the collecting piece inasmuch as the ferrules puncture the silicone rubber material.
3. Objectives
A principal objective of the present invention is to provide a practical milking system which reduces the cyclic vacuum variations at the ends of the teats of the animal being milked and which otherwise occur due to opening and closing of the inflations of the other milking cups and by one or more milking cups falling from the teat of the animal.
A particular objective of the invention is to provide a system in which four separate milk channels are provided from the respective milking cups to the milk line or pail, with a novel collector member for collecting or bringing together the vacuum hose lines from the respective milking cups in closely spaced arrangement beneath the udder of the animal being milked.
A further objective of the invention is to provide a collector member which is associated with the vacuum hose lines from the milking cups so that the weight of the collector member is supported through the vacuum hoses and the milking cups by the teats of the animal being milked, but wherein the collector member has no milk contacting surfaces.
A further objective of the invention is to provide a collecting member which permits the use of silicone rubber vacuum hose lines and protects the hose lines from damage.
An additional objective of the invention is to provide a collector member which has no ferrules to puncture and harm silicone rubber tubing used as vacuum hose lines from the milking cups.
An additional objective of the invention is to provide a collecting member which has means for simultaneously closing off the vacuum in all the vacuum hose lines to the milking cups.
A still further objective of the invention is to provide a milking system in which sanitation is promoted by using silicone rubber vacuum hoses which are very easily cleaned and which do not have surface cracks and irregularities to provide a habitat for bacteria.
A further objective of the invention is to provide a novel teat cup in combination with the novel collecting member wherein the teat cup has built thereinto a unique valving means adapted to closing the vacuum hose line attached to the teat cup whenever the teat cup falls from a teat of the animal being milked.